to veer off course due to chronic laziness, pessimistic ideals, malicious intent; especially when trying to complete a to-do-list.
Jack was pulling a murtagh when he decided against keeping his friends company at Van Saun Zoo.
This word is used when circumstances become seriously dire.
"My granny died last week" saids Chipper
"Thats grimshaw murtagh mate, sorry to hear about that" says Steve